Embodiments of the inventive subject matter generally relate to the field of powerline communications, and, more particularly, to variable line cycle adaptation.
Electric transmission and distribution lines are typically used for providing electric power from generators to buildings, residences, and other infrastructure. Electric power is transmitted over the transmission lines at a high voltage, and distributed to buildings and other structures at much lower voltages using electric powerlines. Besides providing electric power, electric powerlines can also be used to implement powerline communications within buildings and other structures. Powerline communications provide a means for networking electronic devices together and for connecting the electronic devices to the Internet. For example, HomePlug® devices can be used for wired broadband networking using IEEE P1901 standards for broadband over powerline communication. However, the powerline may be susceptible to periodic noise. For example, a dimmer switch may cause a periodic power spike or drain (or other noisy condition) on the powerline. Communication on the electrical wiring is also subject to variations in the channel characteristics and variations in the noise level that are common on the electrical wiring in a building, such as a home.
Communication technology is evolving to support better channel estimation and adaptation of transmissions over a communication channel. For example, in many technologies, such as powerline communications, a medium between a first device and a second device may support periodic channel adaption based on channel conditions. Indicators that may be used as a measurement of the quality of a transmission via a signal (e.g. via a frequency) include the signal-to-noise ratio (SNR) or signal-to-interference-plus-noise (SINR). The formula for SINR may be defined as P/(I+N) where P represents the received power, I represents the interference power of other simultaneous transmissions, and N represents the noise (such as background or intermittent noise). Often, “noise” will be defined to include interference as well as background noise or intermittent noise. Therefore, when measuring signal to noise ratio, the measurement may be referred to as SNR or SINR interchangeably in some systems.